Power Quality Monitoring

▼Chapter 5OPC serverModbus Suite TOP ServerJanitza electronics ® GmbH has been recommending the proven and cost-effective OPC Top server with Modbus suite fromSoftware Toolbox (www.softwaretoolbox.com) for years. Support is also provided in connection with UMG measuring instrumentsand power analysers.Functions of the OPC serverThe OPC server is a software driver and must be installed on a PC in the network. If the existing automation software is alreadyrunning on a computer with sufficient power reserves and if the operating system is compatible with the OPC server, installation ispossible on this computer. If sufficient power reserves are available, the OPC server also runs on systems in which GridVis is alreadyinstalled. The software driver contains a Modbus TCP/IP or a Modbus over TCP/IP Master and an OPC server. The data (e.g. measurementvalues) is read out using the Ethernet interface (port 502 or port 8000) and is passed on to the OPC server. The OPC serverthen passes on the data to the OPC client of the external program. Access can be simultaneously gained to up to 6 software applica -tions on port 502 of the UMG 507E/EP and UMG 604E/EP. Another two applications can be simultaneously accessed on down streammeasuring instruments using the RS485 (Ethernet encapsulation). This means that measurement data can be simultaneously read withGridVis and the OPC server.Configuration of the OPC server▼The OPC server is configured using aconvenient operating area but does requiresome basic knowledge of the data types(Word, float etc) and bus technology.Communication settings can be individuallyadapted for each channel.Following data typesare supported:Char, Byte, Long, Float, Word andDouble as big-endian and little-endian.The OPC server also contains an OPCQuick Client for quick online control ofthe data. This means that the data isautomatically taken from the configurationtable and displayed. The statistics functionassists fault detection.Illustration: Determining OPC variablesIllustration: Communication settingsThe meaning of OPCOPC is an abbreviation for “OLE for processcontrol” and is a standardised interfacein the field of automation technology.This term is frequently used in the field ofbuilding automation. OPC was created toprovide industrial bus systems and protocolswith a universal communication possibility.An OPC driver can be integratedinto any size control and monitoringsystem without any major adaptationefforts.Illustration: OPC Quick Client155